Those look like Surface models only, they don't appear to have the "guts" like a true 3D model would.i just found a couple of 3D CAD models (23 and 26 foot) that look really nice. Not sure about accuracy though: https://www.turbosquid.com/Search/Index.cfm?keyword=GMC+motorhome+&media_typeid=2. The chassis is definitely wrong.
Thanks Christo.Gotta start somewhere
Also check out https://www.gmcmi.com/wp-content/uploads/2017/05/Transmode-Sales-Dev-Guide.pdf as it has builder's guides and measurements as well for upfitting an empty coach.